Under the direction of Dr. Prober, subjects have been enrolled in a trial evaluating the safety, immunogenicity, and efficacy of a recombinant vaccine against herpes simplex virus type 2 (HSV-2). This trial is a multicentered, randomized, placebo-controlled evaluation of a glycoprotein based vaccine developed by Chiron Biocine, Emeryville, CA. Enrollees were HSV-2 uninfected sexual partners of HSV-2 infected subjects. Interim evaluation of vaccine efficacy failed to demonstrate benefit and the study was prematurely discontinued by the sponsor. Nonetheless, T-cell recognition of common and type-specific HSX glycoproteins was measured in the 21 study subjects enrolled at Stanford and these responses currently are being analyzed so that they can be compared with the resposes of naturally infected individuals.